gprs/gprs_llc: fix null pointer deref in gprs_llc_rcvmsg

Change-Id: I1f7e1d524042134c93a4f3de599c54d442447512
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
index 32920da..a2ffa51 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -859,8 +859,7 @@
 		case GPRS_SAPI_SNDCP9:
 		case GPRS_SAPI_SNDCP11:
 			/* Ask an upper layer for help. */
-			return gsm0408_gprs_force_reattach_oldmsg(msg,
-								  lle->llme);
+			return gsm0408_gprs_force_reattach_oldmsg(msg, NULL);
 		default:
 			break;
 		}